The parents of the only United States soldier captured and still held in Afghanistan are breaking their silence, urging Washington to do more to secure his release.

Bob and Jamie Bergdahl spoke Wednesday with their local newspaper, the Idaho Mountain Express, saying they are "frustrated with how slowly the process has evolved." Bob Bergdahl said he is "pushing hard" for the U.S. government and President Barack Obama to secure his son's release through a prisoner swap, fearing any military rescue mission might result in his son's death.

The Bergdahl's comments come almost three years after their son, Private Bowe Bergdahl, disappeared from his base in Afghanistan's eastern Paktika province. The Taliban have since released several videos showing Bowe Bergdahl in apparent good health, even exercising. But the videos also show a young man who seems increasingly desperate to come home.

In one of the videos, Bergdahl says, "The pain in my heart to see my family again doesn't get any smaller." He then says, "Release me, please. I am begging you. Bring me home."

U.S. military officials say they have been working to secure Bergdahl's release and the director of the U.S. Defense Department press office, Colonel Dave Lapan, said, “I wouldn’t rule anything in or out.”

Western news agencies say much of the U.S. effort, so far, has tied Bergdahl's fate to confidence-building measures that had been part of now-stalled peace talks with the Taliban. Specifically, they say negotiators thought they had worked out a deal that would have set the now 26-year-old Bergdahl free following the proposed transfer of five Taliban prisoners from the U.S. detention facility at Guantanamo Bay, Cuba to Qatar. However, the deal felt apart when the Taliban walked out on talks with the United States in March and likely would have faced intense scrutiny in Congress.

The news agencies said they had known about Bergdahl's role in the prisoner swap proposal but had agreed not to report it at the request of the White House, which had warned any public discussion would have endangered Bergdahl's life. They said they were reporting the details now only because Bergdahl's parents had chosen to speak out.

Bergdahl's father, Bob, told the Idaho Mountain Express that the family had also kept quiet until now in the hopes of keeping their son safe while giving U.S. officials time to secure his release. But Bob Bergdahl said he is increasingly worried that his son's life is in danger.

He said "Bowe's been [living] under the drone program the entire time," referring to U.S. military's use of unmanned aircraft to bomb Taliban positions, adding "it scares the hell out of us."

Renewed talk of Bowe Bergdahl's plight also comes at another sensitive point in Afghan-U.S. relations. The United States is set to withdraw all combat troops from Afghanistan by 2014, at which time Afghan forces will take total responsibility for security.

The head of the transition process, Ashraf Ghani Ahmadzai, told reporters Thursday that security conditions have, at the least, not gotten worse and that in some cases they have improved. But he also warned the final stages of the security transfer would amount to a "national survival test."

Meanwhile, the Taliban claimed responsibility Thursday for a botched-suicide bombing in the Yayakhil district of Paktika province.

Afghan officials said six suicide bombers were trying to attack a government building when they were stopped at a military checkpoint. A gun battle broke out. Four of the suicide bombers detonated their vests, while the remaining two were killed in the shootout.

Afghan officials say at least three security officials were killed.

And in the south, authorities say a roadside bomb has killed seven civilians, including children, in Helmand province's Musa Qala district.

Officials say another blast hit local forces who arrived at the scene to help the victims of Thursday's bombing, killing one person.